Gregorio Herdoiza

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We present the results of a lattice QCD calculation of the average up-down and strange quark masses and of the light meson pseudoscalar decay constants with Nf = 2 dynamical fermions. The simulation is carried out at a single value of the lattice spacing with the twisted mass fermionic action at maximal twist, which guarantees automatic O(a)-improvement of(More)
In a recent paper [1] we presented precise lattice QCD results of our European Twisted Mass Collaboration (ETMC). They were obtained by employing two mass-degenerate flavours of twisted mass fermions at maximal twist. In the present paper we give details on our simulations and the computation of physical observables. In particular, we discuss the problem of(More)
We present the results of a quenched lattice QCD study of the coupling ĝ, in the static heavy quark limit. After combining this with our previous results obtained by using propagating heavy quarks with a mass around the physical charm quark, we are able to interpolate to the b-quark sector. Our results are ĝ∞ = 0.48±0.03±0.11, ĝb = 0.58 ± 0.06± 0.10, and(More)
We review some decays that require knowledge of the decay constants of 0 heavy-light mesons. We compute the decay constants of P-wave heavy-light mesons from unquenched lattice QCD at a single lattice spacing. For the charm-strange meson we obtain the decay constant: fD s 0+ = 340(110) MeV using our normalisation conventions. We obtain the f Ps(More)
We present an update of the results for pion mass and pion decay constant as obtained by the ETM collaboration in large scale simulations with maximally twisted mass fermions and two mass degenerate flavours of light quarks. We discuss the continuum, chiral and infinite volume extrapolation of these quantities as well as the extraction of low energy(More)
We apply finite-size recursion techniques based on the Schrödinger functional formalism to determine the renormalization group running of four-fermion operators which appear in the ∆S = 2 effective weak Hamiltonian of the Standard Model. Our calculations are done using O(a) improved Wilson fermions with Nf = 2 dynamical flavours. Preliminary results are(More)
  • A Abada, D Be´cirevi´c, +5 authors Quintero
  • 2002
The strong coupling constant g HHπ of heavylight mesons and a soft pion is one of the essential parameters entering the lagrangian which englobes both the chiral and the heavy quark symmetry [1]. Its precise value is useful in evaluating the nearest pole contribution to the shape of the B → π and D → π semileptonic decay form factor, since the residua are(More)